1. Field of the Invention
The present invention is related to a combination structure of a motor and, more particularly, to a combination structure of a motor that has at least one assembly hole on each of a base board and a printed circuit board for containing at lease one sensing unit to decrease an axial height of the combination structure.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a prior art motor structure, such as Taiwanese patent publication No.456667 “Combination Structure for DC brushless motor”, includes a base board 10, a printed circuit board 20, a stator 30 and a rotor 40. The base board 10 has an axle tube adapted to assemble the printed circuit board 20, the stator 30 and the rotor 40. At least one sensing unit 50 is welded on an upper surface of the printed circuit board 20. The sensing unit 50 is placed below an annular magnet 41 of the rotor 40 and is used for sensing the annular magnet 41. The printed circuit board 20 can alternatively activate the stator 30 to cause rotation of the rotor 40.
Although the prior art motor has a simple structure, as shown in FIG. 2, during assembly of the prior art motor, the sensing unit 50 needs to be placed facing the annular magnet 41 and welded on the upper surface of the printed circuit board 20. Hence, the sensing unit 50 occupies space and increases an axial height of the prior art motor, which causes the prior art motor to be unsuitable for a small size electronic device, such as a thin optical disk drive.
Therefore, it is desirable to provide an improved motor design to mitigate and/or obviate the aforementioned problems. The present invention provides at least one assembly hole on each of the base board and the printed circuit board to contain the sensing unit. In this way, the sensing unit can avoid an increase of the axial height of the motor, which carries out a decrease of dimensions of the motor.